Backing paper for roll coating film



Au 9, 1938. P. c. SEEL 2,126,350

BACKING PAPER FOR ROLL COATING FILM Fild April 3. 1937 CELLULOSE E THYL E THER I v P 1g. 2

WIIIIIIIIIIIIIIIIIIIIIIIIIIIIMIA CELLULOSE ETHYL ETHER DUPLEX PAPER Paul C. Seel INVENT OR.

BY J01, M

ATTORNEYS Patented Aug. '9, 1938 a I.

UNITED STATES PATENT OFFICE BACKING PAPER FOR ROLL COATING FILM Paul C. Seel, Rochester, N. Y., asslgnor to Eastman Kodak Company, Rochester, N. Y., a cornotation of New Jersey Application April 3, 1937, Serial No. 134,913

3 Claims. (0].. 95-9) This invention relates to photographic roll suitable solvent. The manner oi application of him backing paper-and particularly to a prothe coating and the manner ofv drying are nontective coating for such paper. essential and may be carried out in any suitable As is'well hnown, sensitive photographic roll way known to the art as long as a thin even him is ordinarily attached to a sheet oi opaque coating on the paper is attained. paper and is rolled on a spool together with the v For example, a 10% solution by weight of paper in order to protect the sensitive suriace cellulose ethyl ether having an ethoxy content irom the action oi light, dust and other agents oi i9.2% is made up in ethylene chloride. This which would adversely adect it. This opaque solution is coated on Duplex paper so that a in leaching sheet is customarily coated with a matecoating approximately .0004" thick is obtained. .10 rial which renders the sheet impervious to mols- The coating is then dried at elevated temperature ture and which does not desensitize or otherwise to remove substantially all the solvent irom it. adversely affect the sensitive layer with which I. will now describe my invention by particular it comes in contact. Various materials have reference to the accompanying drawing. in Fig. i it heen used for coating the leaching paper used in I have shown a sectional view oi a roll him comis roll him. Cellulose nitrate has been used ior this prising a sensitive him is attached to the leaching purpose, hut it is unsatisfactory hecause oi its paper l i lay an adhesive strip ii. The haching high inhammahility and its tendency to instapaper is oi sumcient length to protect the sensihillty in contact with impurities in the paper. tive him irom light and is attached to the spool id Cellulose organic esters, such as cellulose aceii at the groove ii.

tate have also been used. Cellulose acetate, howin Fig. 2 l have shown an enlarged sectional ever, is susceptible to moisture and does not give view oi a sheet o'i Duples paper it coated with a complete protection to the sensitive suriace. layer oi cellulose ethyl other i hy "Duplex; pal ully esterihed esters, such as cellulose acetate per i mean a paper so constructed that two J or cellulose acetate propionate are not as de separate sheets, usually differently colored, are sirahle hecause the choice oi solvents irom which handed together to iorm a unitary structure. they may he coated is unite limited, the good it is to he understood that, although this type solvents losing somewhat tonic. Moreover, a so oi paper is usually used, other types may also rious didlculty is encountered in the use oi many he employed, according to my invention. oi these materials hecause there is incomplete i have re'ierred shore to the use oi cellulose bonding between the paper and the coating. in ethyl ether ior coating the leaching mper. It is many cases the coating is uneven or easily lcrohen to he understood, however, that other cellulose and this gives rise to much waste material. alhyl others may he used. such as cellulose methyl it is, thereiore, an object oi the present inven ether. Cellulose allwl others having a wide range 5 tion to provide an improved leaching paper ior oi characteristics may he employed. Cellulose roll him which is stahle in contact with impurialhyl others having a high alhory content are ties in the paper and which is not highly sus preferred, since these compounds are onlyslightly ceptihle to moisture. a iurther object is to prosusceptible to moisture. Cellulose alkyi others vide a coating which is tightly handed to the having an alhosy range oi about it?" to 55% paper and which does not crash or peel when may he used, although i am not particularly limthe paper is creased. Other objects will appear ited to this range. in order to coat them on the irom. the iollowing description oi my invention. haching paper. the ethers may be dissolved in These oloiects are accomplished by coating the solvents other than ethylene dichloride, many leaching paper used in roll him with a layer oi oi which are available, such as acetone, ethyl a cellulose alhyl other, such as cellulose ethyl aciithliii'yblllilli acetate, propylene dichloride alone ether having a high alhouy content; or with methyl alcohol, methyl alcohol alone or in the'accompanying drawing. his. i is a secwith hencene, ethyl alcohol, ethylene glycol mono tional view oi a portion of a roll him and spool methyl ether and dioxane. thereior showing the relation oi the hacking Various plasticizers and resins may he used if as paper to the sensitive film. desired such as triphenyl phosphate, diethyl 50 Fig. 2 is "an enlarged sectional view of the phthalate. mono cresyl paratoluene sull'onate backing paper. castor oil, ester gum, gum dammar,- etc. These The backing paper is coated according to my compounds when mixed with the ethers have invention by applying to it' a solution oi a ceilu the street of increasing the flexibility o! the 1 lose alkyl ether 0! high alkoxy content from acoating.

Among the advantages of cellulose alkyl ethers over backing paper coatings previously used are good adherence to the paper, little tendency to show white lines or cracks when the paper is creased, only slight tendency to pull away from the paper. less sensitivity to abrasion, and a greater tendency to "level out on the paper when coated, rather than to follow the contours oi. the paper pattern. All of these advantages produce a superior backing paper coating. Moreover; due to its higher compatibility with. othercoatings, it may be more conveniently coated over other coatings present on the surface of the paper, such as dye coatings, inks, sizing layers. and the like.

Coatings of various thickness may be made by using solutions of various strength and by coating at diiferent speeds. The thickness oi! the coating is limited only by convenience and economy in application on one hand and by complete protection to the surface of the paper on the other hand. It is to be understood that numer- 01'. high ethoxyl content.

ous other modifications may be made within the spirit of my invention, the breadth of which is to be measured by the scope of the appended claims.

What I claim is:

1. A photographic roll film backing paper comprising an opaque paper coated with a layer of cellulose ethyl ether of high ethoxyl content.

2. A photographic roll film backing P per comprising an opaque paper coated with a layer of cellulose ethyl ether having an ethoxyl content of about 49%.

3. A photographic roll film comprising a cellulosic sheet having on one side thereof a sensitized layer, and attached to the opposite side thereof a sheet of opaque paper coated on the side opposite that to which the sensitized iilm is attached, with a layer of cellulose ethyl ether PAUL C. SEEL. 

